improved compression test

git-svn-id: http://svn.code.sf.net/p/retroshare/code/branches/v0.6-IdCleaning@7145 b45a01b8-16f6-495d-af2f-9b41ad6348cc
fixed stupid bug in decompression code

git-svn-id: http://svn.code.sf.net/p/retroshare/code/branches/v0.6-IdCleaning@7146 b45a01b8-16f6-495d-af2f-9b41ad6348cc